Patent document 1 describes an example of a known valve timing controller of the internal combustion engine. Such a valve timing controller, including that described in patent document 1, is provided with a variable mechanism including a first rotating body, which moves in cooperation with a crankshaft, and a second rotating body, which moves in cooperation with a camshaft. The variable mechanism supplies and discharges hydraulic oil to and from a plurality of hydraulic pressure chambers defined by the rotating bodies to relatively rotate the rotation bodies about the same axis and control the rotation phase of the camshaft relative to the crankshaft, that is, control the valve timing at a phase corresponding to the engine operation state. The supply and discharge of the hydraulic oil to the hydraulic pressure chambers are performed through a supply/discharge path extending from the respective hydraulic pressure chamber towards the axis of the rotating bodies.
In addition to the variable mechanism, the valve timing controller includes a lock mechanism that locks the valve timing at a specific phase by restricting relative rotation of the two rotating bodies when the hydraulic pressure of the hydraulic pressure chamber is low.